'use strict';

import AxiosError from '../core/AxiosError.js';
import parseProtocol from './parseProtocol.js';
import platform from '../platform/index.js';

const DATA_URL_PATTERN = /^(?:([^;]+);)?(?:[^;]+;)?(base64|),([\s\S]*)$/;

/**
 * Parse data uri to a Buffer or Blob
 *
 * @param {String} uri
 * @param {?Boolean} asBlob
 * @param {?Object} options
 * @param {?Function} options.Blob
 *
 * @returns {Buffer|Blob}
 */
export default function fromDataURI(uri, asBlob, options) {
    const _Blob = options && options.Blob || platform.classes.Blob;
    const protocol = parseProtocol(uri);

    if (asBlob === undefined && _Blob) {
        asBlob = true;
    }

    if (protocol === 'data') {
        uri = protocol.length ? uri.slice(protocol.length + 1) : uri;

        const match = DATA_URL_PATTERN.exec(uri);

        if (!match) {
            throw new AxiosError('Invalid URL', AxiosError.ERR_INVALID_URL);
        }

        const mime = match[1];
        const isBase64 = match[2];
        const body = match[3];
        const buffer = Buffer.from(decodeURIComponent(body), isBase64 ? 'base64' : 'utf8');

        if (asBlob) {
            if (!_Blob) {
                throw new AxiosError('Blob is not supported', AxiosError.ERR_NOT_SUPPORT);
            }

            return new _Blob([buffer], {type: mime});
        }

        return buffer;
    }

    throw new AxiosError('Unsupported protocol ' + protocol, AxiosError.ERR_NOT_SUPPORT);
}
